/*
 * @(#)JdbcDriverImpl.java
 *
 * @author	  Orlin Tomov
 * 
 */

package dbu.jdbc.facade;

import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverPropertyInfo;
import java.sql.SQLException;
import java.util.Properties;

/**
 * The interface that every driver class must implement.
 * <P>The Java SQL framework allows for multiple database drivers.
 *
 * <P>Each driver should supply a class that implements
 * the Driver interface.
 *
 * <P>The DriverManager will try to load as many drivers as it can
 * find and then for any given connection request, it will ask each
 * driver in turn to try to connect to the target URL.
 *
 * <P>It is strongly recommended that each Driver class should be
 * small and standalone so that the Driver class can be loaded and
 * queried without bringing in vast quantities of supporting code.
 *
 * <P>When a Driver class is loaded, it should create an instance of
 * itself and register it with the DriverManager. This means that a
 * user can load and register a driver by calling
 * <pre>
 *   <code>Class.forName("foo.bah.Driver")</code>
 * </pre>
 *
 * @see DriverManager
 * @see Connection 
 */
public abstract class JdbcDriverImpl implements Driver {

	/**
	 * Attempts to make a database connection to the given URL.
	 * The driver should return "null" if it realizes it is the wrong kind
	 * of driver to connect to the given URL.  This will be common, as when
	 * the JDBC driver manager is asked to connect to a given URL it passes
	 * the URL to each loaded driver in turn.
	 *
	 * <P>The driver should throw an <code>SQLException</code> if it is the right 
	 * driver to connect to the given URL but has trouble connecting to
	 * the database.
	 *
	 * <P>The <code>java.util.Properties</code> argument can be used to pass
	 * arbitrary string tag/value pairs as connection arguments.
	 * Normally at least "user" and "password" properties should be
	 * included in the <code>Properties</code> object.
	 *
	 * @param url the URL of the database to which to connect
	 * @param info a list of arbitrary string tag/value pairs as
	 * connection arguments. Normally at least a "user" and
	 * "password" property should be included.
	 * @return a <code>Connection</code> object that represents a
	 *		 connection to the URL
	 * @exception SQLException if a database access error occurs
	 */
	@Override
	public Connection connect(String url, Properties info) throws SQLException {
		throw new SQLException("not supported");
	}

	/**
	 * Retrieves whether the driver thinks that it can open a connection
	 * to the given URL.  Typically drivers will return <code>true</code> if they
	 * understand the subprotocol specified in the URL and <code>false</code> if
	 * they do not.
	 *
	 * @param url the URL of the database
	 * @return <code>true</code> if this driver understands the given URL;
	 *		 <code>false</code> otherwise  
	 * @exception SQLException if a database access error occurs
	 */
	@Override
	public boolean acceptsURL(String url) throws SQLException {
		throw new SQLException("not supported");
	}

	/**
	 * Gets information about the possible properties for this driver.
	 * <P>
	 * The <code>getPropertyInfo</code> method is intended to allow a generic 
	 * GUI tool to discover what properties it should prompt 
	 * a human for in order to get 
	 * enough information to connect to a database.  Note that depending on
	 * the values the human has supplied so far, additional values may become
	 * necessary, so it may be necessary to iterate though several calls
	 * to the <code>getPropertyInfo</code> method.
	 *
	 * @param url the URL of the database to which to connect
	 * @param info a proposed list of tag/value pairs that will be sent on
	 *		  connect open
	 * @return an array of <code>DriverPropertyInfo</code> objects describing 
	 *		  possible properties.  This array may be an empty array if 
	 *		  no properties are required.
	 * @exception SQLException if a database access error occurs
	 */
	@Override
	public DriverPropertyInfo[] getPropertyInfo(String url, Properties info) throws SQLException {
		throw new SQLException("not supported");
	}

	/**
	 * Retrieves the driver's major version number. Initially this should be 1.
	 *
	 * @return this driver's major version number
	 */
	@Override
	public int getMajorVersion() {
		throw new RuntimeException("not supported");
	}

	/**
	 * Gets the driver's minor version number. Initially this should be 0.
	 * @return this driver's minor version number
	 */
	@Override
	public int getMinorVersion() {
		throw new RuntimeException("not supported");
	}

	/**
	 * Reports whether this driver is a genuine JDBC
	 * Compliant<sup><font size=-2>TM</font></sup> driver.
	 * A driver may only report <code>true</code> here if it passes the JDBC
	 * compliance tests; otherwise it is required to return <code>false</code>.
	 * <P>
	 * JDBC compliance requires full support for the JDBC API and full support
	 * for SQL 92 Entry Level.  It is expected that JDBC compliant drivers will
	 * be available for all the major commercial databases.
	 * <P>
	 * This method is not intended to encourage the development of non-JDBC
	 * compliant drivers, but is a recognition of the fact that some vendors
	 * are interested in using the JDBC API and framework for lightweight
	 * databases that do not support full database functionality, or for
	 * special databases such as document information retrieval where a SQL
	 * implementation may not be feasible.
	 * @return <code>true</code> if this driver is JDBC Compliant; <code>false</code>
	 *		 otherwise
	 */
	@Override
	public boolean jdbcCompliant() {
		throw new RuntimeException("not supported");
	}
}
